On the right drawing of a hornet's nest (Vespa crabro). Hornets' preferred nesting site is in an old tree. The nest is similar to a wasp's, i.e. it is constructed of chewed wood mixed with saliva. The wood is obtained from unpainted fence posts, fences, tree trunks, and garden furniture that is unvarnished or treated.
Unlike the social bees, hornets have no wax glands and construct their nests out of chewed wood mixed with their own saliva.
A successful hornet nest has about 200 workers at most, but many have far fewer.
Hornet body lengths are, queens are 29 - 38 mm, workers 22 - 24 mm, and males 29 - 35 mm.
Like bumblebees workers maintain the nest at a steady temperature of around 30oC regardless of the outside temperature.